<template>
  <div>
    <nav-bar class="nav-bar">
      <template v-slot:default>
        购物车(<span style="color:red"> {{$store.state.cartCount}} </span>)
      </template>
    </nav-bar>
    <div class="cart-box">
      <div class="cart-body">
        <van-checkbox-group ref="checkboxGroup" @change="groupChange" v-model="result">
          <van-swipe-cell :right-width="50" v-for="(item, index) in list" :key="index">
            <div class="good-item">
              <van-checkbox :name="item.id" />
              <div class="good-img"><img src="~assets/images/11.png" alt=""></div>
              <div class="good-desc">
                <div class="good-title">
                  <span>{{item.goods.title}}</span>
                  <span>x{{item.goods.stock}}</span>
                </div>
                <div class="good-btn">
                  <div class="price"><small>¥</small>{{item.goods.price + '.00'}}</div>
                  <van-stepper integer :min="1" :max="item.goods.stock" :model-value="item.num" :name="item.id" async-change
                               @change="onChange"/>
                </div>
              </div>
            </div>
            <template #right>
              <van-button
                  square
                  icon="delete"
                  type="danger"
                  class="delete-button"
                  @click="deleteGood(item.id)"
              />
            </template>
          </van-swipe-cell>

        </van-checkbox-group>
      </div>
      <van-submit-bar class="submit-all" :price="total * 100" @submit="onSubmit" button-text="结算">
        <van-checkbox @click="allCheck" v-model:checked="checkAll">全选</van-checkbox>
      </van-submit-bar>
      <div class="empty" v-if="!list.length">
        <img class="empty-cart" src="~assets/images/empty-car.png" alt="空购物车">
        <div class="title">购物车空空如也</div>
        <van-button round color="#1baeae" type="primary" block @click="goTo">前往选购</van-button>
      </div>

    </div>

  </div>
</template>

<script>
import {ref, reactive, toRefs, onMounted, computed} from 'vue';
import { useRouter } from 'vue-router'
import { useStore } from 'vuex'
import {getCart, deleteCartItem, checkedCart, modifyCart} from 'network/cart'
import { Toast } from 'vant'
import NavBar from "components/common/navbar/NavBar";
export default {
  name: "ShopCart",
  setup() {
    const router = useRouter()
    const store = useStore()

    // 数据模型， 状态
    const state = reactive({
      list: [],
      result:[], //id数组
      checkAll:true
    })

    // 初始化购物车数据
    const init = ()=>{
      Toast.loading({message:'加载中...', forbidClick:true});
      getCart('include=goods').then(res=>{
        state.list = res.data;
        console.log(res.data);
        state.result = res.data.filter(n=>n.is_checked == 1).map(item => item.id);
        Toast.clear();
      })
    }

    onMounted(()=>{
      init();
    })
    // 通过计算属性 计算总价
    const total = computed(()=>{
      let sum = 0;

      state.list.filter(item=> state.result.includes(item.id))
          .forEach(item =>{
            sum += parseInt(item.num) * parseFloat(item.goods.price);
          })

      return sum;
    })

    // 异步改变购物车数量
    const onChange = (value, detail) => {
      Toast.loading({message:'修改中...', forbidClick:true});

      modifyCart(detail.name, {num:value}).then(res=>{
        //将在onMounted中的list中的num也要改
        state.list.forEach(item => {
          if(item.id == detail.name) {
            item.num = value;
          }
        })

        Toast.clear();
      })

    }

    // 复选框改变处理
    const groupChange = (result) => {
      if(result.length == state.list.length) {
        state.checkAll = true;
      }else{
        state.checkAll = false;
      }

      console.log(result);

      state.result = result;
      // 改变数据表中选中状态
      checkedCart({cart_ids:result});
    }

    const allCheck = ()=>{
      if(!state.checkAll) {
        state.result = state.list.map(item=>item.id)
        state.checkAll = true;
      }else {
        state.result =[];
        state.checkAll = false;
      }
    }

    // 前往购物
    const goTo = ()=>{
      router.push({path:'/home'});
    }

    // 删除商品
    const deleteGood = (id) =>{
      deleteCartItem(id).then(res=>{
        init(); //重新初始化
        store.dispatch('updateCart'); //改变vuex中的状态数量
      })
    }

    // 创建定单
    const onSubmit = () => {
      if(state.result.length == 0) {
        Toast.fail("请选择商品进行结算");
        return;
      }else{
        router.push({path:'/createorder'});
      }
    }

    return {
      ...toRefs(state),
      goTo,
      onChange,
      groupChange,
      allCheck,
      deleteGood,
      total,
      onSubmit
    }
  },


  components: {
    NavBar
  }
}
</script>

<style scoped lang="scss">
.cart-box {
  .cart-body {
    margin: 60px 0 100px 0;
    padding-left: 10px;
    .good-item {
      display: flex;
      .good-img {
        img {
          width:100px;
          height:auto;
        }
      }
      .good-desc {
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        flex: 1;
        padding: 20px;
        .good-title {
          display: flex;
          justify-content: space-between;
        }
        .good-btn {
          display: flex;
          justify-content: space-between;
          .price {
            font-size: 16px;
            color: red;
            line-height: 28px;
          }
          .van-icon-delete {
            font-size: 20px;
            margin-top: 4px;
          }
        }
      }
    }
    .delete-button {
      width: 50px;
      height: 100%;
    }
  }
  .empty {
    width: 50%;
    margin: 0 auto;
    text-align: center;
    margin-top: 200px;
    .empty-cart {
      width: 150px;
      margin-bottom: 20px;
    }
    .van-icon-smile-o {
      font-size: 50px;
    }
    .title {
      font-size: 16px;
      margin-bottom: 20px;
    }
  }
  .submit-all {
    margin-bottom: 50px;
    .van-checkbox {
      margin-left: 0px
    }
    .van-submit-bar__text {
      margin-right: 10px
    }
    .van-submit-bar__button {
      background:red;
    }
  }
  .van-checkbox__icon--checked .van-icon {
    background-color:red;
    border-color: red;
  }
}
</style>